1. Field of the Invention
The present invention relates to a liquid treating method and a liquid treating apparatus that are applicable in the fields involving gas dissolution such as hydroponic industries. More specifically, the present invention relates to a method and an apparatus for dissolving gas into liquid or improving liquid quality by colliding vibration waves, such as ultrasonic waves and sound waves, to bubbles.
2. Related Background Art
To dissolve a gas or gasses into a liquid phase is one of the important steps in various fields. For example, addition of oxygen to water can improve efficiency of hydroponic cultivation, enhance effective feeding of oxygen to cultured fishes, shells and so on in a farm, and reduce a fermentation period required to fermentate beer, whisky, Japanese sake, soy source, breads, and tofu.
Gas introduction into a liquid phase is typically achieved by releasing it through a gas diffusing pipe into the liquid phase to form bubbles. To increase gas-absorbing efficiency of the liquid through such bubbling, Japanese Patent Laid Open No. 61-227824 proposes irradiation of ultrasonic waves to the bubbles to make the latter fine.
On the other hand, Japanese Patent Laid Open No. 5-115898 discloses a water treating method, in which the water is subjected to ultrasonic waves, magnetic fields, and far-infrared radiation successively in this order.
However, the former two methods are disadvantageous by the efficiency considerations. More specifically, these methods allow the bubbles to be dissolved spontaneously into the liquid phase. This means that a solution velocity of the bubbles into the liquid phase is decreased as the liquid phase becomes closer to saturation, increasing the gas proportion therein. The liquid phase hence reaches saturation only after a long-time bubbling of the gas.
In addition, the latter method of treating water has no specific disclosure on an ultrasonic treatment.
Accordingly, an object of the present invention is to provide a method and an apparatus for dissolving a gas effectively into a liquid phase.
Another object of the present invention is to provide effective method and apparatus for improving liquid quality with vibration waves.